Survivors of the surprise Japanese attack on Pearl Harbor gathered Wednesday to remember the 2,400 people who lost their lives exactly 70 years ago.

"Just as every day and unlike any other day, we stop and stand fast in memory of our heroes of Pearl Harbor and the Second World War," Rear Adm. Frank Ponds, commander for Navy region Hawaii, told the gathering.

U.S. Secretary of the Navy Ray Mabus took note of the devastating legacy of the two-hour attack on Pearl Harbor 70 years ago.

"The history of December 7, 1941, is indelibly imprinted on the memory of every American who was alive that day. But it bears repeating on every anniversary, so that every subsequent generation will know what happened here today and never forget," Mabus said.

At the Pearl Harbor visitor center in Hawaii, about 5,000 guests witnessed a rifle salute, wreath presentations and recognition of those who died. The National Park Service operates the World War II Valor in the Pacific National Monument, and the venue overlooks the USS Arizona memorial.

At 7:55 a.m., the exact moment the attack began, F-22s flew over the ceremony in a "missing man" formation, and a moment of silence was observed. A U.S. Navy ship rendered honors to the Arizona.

Remains of Vernon Olsen, 91, of Port Charlotte, Florida, were to be interred later Wednesday in the USS Arizona, the battleship on which he served and where 1,117 sailors and Marines died in the attack.

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In a statement, President Barack Obama said the veterans and survivors of Pearl Harbor are an inspiration.

"Despite overwhelming odds, they fought back heroically, inspiring our nation and putting us on the path to victory," Obama said.

"They are members of that Greatest Generation who overcame the Depression, crossed oceans and stormed the beaches to defeat fascism, and turned adversaries into our closest allies. When the guns fell silent, they came home, went to school on the G.I. Bill, and built the largest middle class in history and the strongest economy in the world. They remind us that no challenge is too great when Americans stand as one."

Flying from aircraft carriers on December 7, 1941, Japanese aviators attacked eight battleships in the harbor, destroying two, and left a trail of death and destruction across the verdant landscape. They also struck other military installations on Oahu.

The attack shook America's confidence and pulled the country into World War II.

About 120 Pearl Harbor survivors attended Wednesday's ceremony.

The gradual loss of the World War II generation has accelerated, and this year, perhaps more than any before, evidence of a tide change is inescapable.

The Pearl Harbor Survivors Association, founded in 1958, is dissolving December 31. The passage of time, the difficulty in finding chapter officers, and the health of its 2,700 members have taken their toll.

In recent years, interpretation of the attack has shifted its focus "from engagement to peace," with recognition that both sides fought a "savage war," said Daniel A. Martinez, chief historian at the national monument.

Martinez and other staff members have recorded video interviews with many veterans, preserving their memories. "They tell me stories they haven't told their families," he said.